Vintage RCA 12AT7 ECC81 Black Plates Vacuum Tube 1958 Very Strong & Balanced


 **** Tested on our  proprietary  tester , the E3444.


It's a Triplett 3444 that has been enhanced.


This tester uses regulated power sources for the bias, plate, & screen voltages, as well as modified operating & testing procedures.


Filament voltage is also controlled. 


Tubes are tested in accordance with the manufacturer's specifications; measurements closely align with a laboratory tester built to rigorously measure vacuum tube characteristics. 


Tubes can be accurately matched for gm & plate current at the manufacturer's specified test points or at other specified test points.


***** This tester was prepared by Mr. Paul Hart of Roswell, GA  

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Industry Bogey transconductance  = 5500|5500 µmhos   

           Industry Bogey plate current =  11.0|11.0mA

                                                Results =5200|4900  µmhos  ~ |mA
             
                                                             
Shipping $6


USA

No Int'l shipping 

All Tubes are Guaranteed 

All orders are combined 


***********Thank you **************